Abstract
This special issue honors them: Edward (Ed) Bouwer (1955-2019), Michael (Mike) Aitken (1956-2020), James (Jim) J. Morgan (1932-2020), Deborah (Deb) Swackhamer (1954-2021), and Philip (Phil) Singer (1942-2020). The 16 papers focus on the innovative microbial and chemical processes for addressing both classic problems (e.g., nutrient recovery and wastewater treatment) as well as emerging problems (e.g., biodiversity loss, plastic pollution, biotransformation of organic chemicals, cyanotoxins, and disinfection byproducts).